TABLE 2.

Comparison of MIC values for aztreonam/avibactam and aztreonam alone as determined concurrently by broth microdilution and agar dilution susceptibility testing against Enterobacterales

Aztreonam/avibactam
			Fold-difference—broth MIC vs. agar MIC
Organism	Na	EAb	≥–8	–4	–2	0	+2	+4	≥+4	≥+8
Enterobacterales	201	97.0%			26	97	72	4		2
E. coli	57	96.5%			12	23	20	1		1
K. pneumoniae	48	97.9%			4	26	17			1
Proteus spp.	20	100.0%			2	10	8
E. cloacae	29	93.1%			2	12	13	2
Citrobacter spp.	18	100.0%			2	12	4
Other	29	96.6%			4	14	10	1

^aNumber of evaluable isolates (isolates for which the fold-difference as indicated could be determined based on the MIC).

^bEA, essential agreement (MIC value identical or within 2-fold between methods; shaded in gray).